Much like consuming some of the local cuisine and local beer, riding the local mass transit when seeing the sights, using a bit of the local language, listening to a local radio station, and doing a bit of grocery shopping to see what sort of things the locals have (or don't have) ...I usually make a point to buy a local SIM card. It's always an educational process (Italy and Spain in particular) and almost always cheaper than any other alternatives.

After a ton of research on the topic I was unsatisfied with nearly all of the "set it up in advance" international SIM options. As much as it scared me, I ended up going with the option in Greece of just going to the Germanos cell phone store in the Athens Airport (who is a dealer for Cosmote, one of their big cell providers). They provided a micro-SIM for my iPhone 4S (which I had unlocked already in the states), and I loaded 13 euro worth of credit on it, which gave me 200 minutes to anywhere in Greece, and 500MB of data, which was plenty for my stay.

It took a few minutes to negotiate what I needed through the slight language barrier, but the whole process only took about 20 minutes, and was far cheaper than anything that involved the convenience of setting it up here in the states. Prepaid cell phone plans are much more popular internationally than in the US (where we are addicted to postpaid contracts), so there are usually LOTS of options.

I think the process, generalized for most international travel would be:

Find the largest few mobile providers in the country you are going to.

Look at their websites to learn about some promotions (extra data if you add 5 euro this month!)

Print a Google Map of a corporate store at the airport or close to your hotel.

Drop in, get a SIM, and add some credit for the minutes/data you need.

Bring your passport, some countries require a scan of your passport before they can issue a phone number to an international customer (such as Greece).

P.S. Be slightly wary of "kiosks". They can usually sell you a prepaid sim, but they usually can't activate it on the spot (they sell a bunch of SIMs through the day, then the next day someone from the company comes to activate them all). This means an activation delay, but more importantly, since you are travelling, there is no way to talk to anyone if the activation doesn't go correctly. If you are at a corporate store they can fix everything on the spot if there is an issue.

Kiosks are fine for buying the re-up cards - they are just a gift-card with a code on it that you text to the cell provider to add more minutes.

Is it really so hard to modify the settings appropriately on the iPhone? I've got a (moderately old now) Android (from Sprint, if that changes anything about the configuration), and when I last traveled abroad (albeit just to Canada - but they do charge roaming rates there, especially for data) it was trivial to disable mobile data, mobile data roaming, and voice roaming. I could even disable all three separately, which was handy when I wanted to switch voice back on and make a brief (overpriced) phone call, without paying for my phone to check email, weather, etcetera. Is this really harder in iOS / AT&T? Or do you just not trust the settings?

I don't think it's about trusting the settings. It's that Mark wants to keep using his phone in the way that is most useful to him, but doesn't want to pay ridiculous roaming rates. US and Canadian cell phone rates are so bad that you can often get a better deal with a prepaid SIM in another country than you do in North America on a contract.

Well, it's because people want to have data when they're travelling now. It's invaluable to have maps, search, maps with search, even social media, while you're on the streets of a new city.

But the myriad phone companies of the world can't agree on a half-reasonable way of charging us for data on other networks (so that we could keep our own phone number), so the best alternative is to go direct to the local carriers.

I thought it was weird, too. It is dead easy to shut off all that stuff in iOS, or selectively shut off data.

I do understand that Mark is always going to get some kind of local usage and/or roaming plan hooked up, but carrying a paperclip to remove the SIM before arrival seems a little silly. Why not just set Mobile Data to OFF before getting on the plane, then reactivate it once you know you won't be connected to your home carrier?

Sure - but I found I could get free WiFi quite often during my day, and so could keep up on email and my surfing needs. Not as good as actually having affordable cellular service - but easier than learning about SIM cards and their plan details!

Too bad HolidayPhone works in precious few countries... like none in Central or South America. Just a handful in Africa. And what's up with having Finland, Sweden & Denmark but no Norway? Malaysia but no Singapore? It's not hard to envision a trip where you'd have to end up buying a local prepaid SIM anyway, as you travel from one country to another where they do not cover.

I'm not sure what travelling a lot has to do with making such a simple thing forgettable. If it is, having a simple to-do list for travel days sounds like a good idea. Maybe the same to-do list that says "don't forget to pack a paperclip".

In any case, don't most or all airlines and/or national aviation authorities have restrictions on in-flight device use (however silly they may be)? That means there's always some point in the trip when you're going to be reminded to turn Airplane Mode on. And in iOS, that setting is right next to the Cellular Data setting.

The only problem with that method is I need data to find the local sim shop. So, from the point I arrive in that country until I get to a sim shop I'm S.O.L. That generally means I'll have to find my hotel without access to my phone or it's maps. Yes, I can prepare ahead (and I do just in case) but that's the whole point of a smartphone's convenience is NOT having to do those things.

I've been using keepgo for the last 2.5 months while in Europe. Whether it's cheap or not like most things depends. I think I'm paying $13 a day for 100meg a day which comes up to ~$400 a month. 100meg is too little for me to freely use the phone but it's enough for me to use google maps if I cache the maps and it's enough for me to browse travel websites for info as I'm out and about. It's not enough for me to post images or read facebook or instagram for hours at some cafe. It's worked well enough in Helsinki, Berlin, Brussels, Antwerp, Brugge, Tromsø, and Amsterdam but it didn't work to well in Stockholm.

$13 a day! Comon, download Navigon maps for the region/country (or some other very high quality set of maps) for <$100 and then you aren't worrying about 3G speeds, daily download limits, etc. When you get to the hotel, ask them about a local kiosk, phone store (the PAYG wikia site will give you the various names), or wherever the locals tend to get SIM cards.

If you're always running around on business and can just expense everything then perhaps the $13 a day isn't a big deal, but if you're traveling on your own money... I highly recommend the Navigon maps + PAYG wikia solution. It's a little adventure, but that's a good thing.

Travelling with a stopover + two young kids + 16 hours in the air + jetlag.

Simple things are easily forgettable under pressure and fatigue.

I just turn the iPhone off in the four seconds I have between cleaning up orange juice and playing airplane logos. Then I arrive, keep it off, turn it on in emergency, and get walloped by the ***thieving**** phone companies.*

The national carrier gets its cut, the provider gets its cut, and I get cut cut cut a thousand times.

If there were any honesty in all this, the phone would turn off data roaming as soon as you left your domestic provider's zone, and inform you when you're in a new zone.

Does Navigon maps support trains routes, bus routes, subway routes and bike routes? (Google Maps does) Does Navigon maps let me use my computer to look stuff up, save the locations I looked up, and sync them to my phone so when I use the map there all the stuff I marked on my computer is on the phone (Google Maps does). Does navigon know what I searched for on my desktop so that it auto completes to stuff I looked up recently on my phone when searching? (Google Maps does) Does Navigon maps let me search with half names like "ibis, amsterdam" instead of having to spell it exactly like it happens to be in their database or having to know the exact address? (Google Maps does). Does Navigon maps show a street view, give me the hours of the shop, restaurant, or attraction and a link to the website of the things I look up? (Google Maps Does)

I ask because I tried some other offline maps app, MapsWithMe, that has none of those features. It was ok for traveling on foot some of the time when it happened to have the thing I was looking for in its database and I could figure out how to find it in its listings that was less than 50% of the time and it had no public transportation routes which made it useless until I was within walking distance.

As for $13 a day, yes that's expensive for a month but it's not expensive for a 4 day trip and might be better than some of the other options. I looked at it as it was better to have something than nothing. AFAIK HolidayPhone doesn't work in Norway, The Netherlands, Belgium, and you have to pick a single country. Where as Keepgo you can just pick all of Europe as your plan.